Project Portugal 2030

Summary

Among the most critical challenges that our society is facing, guaranteeing access to clean water and tackling bacterial and viral infections are critical aspects to achieve a sustainable development. The discharge of oil from human activities into water bodies has substantial repercussions on water ecosystems and marine organisms [4,5]. Simultaneously, bacterial, fungi and viral infections pose the risk of life-threatening conditions, significant social disruption, and potential global health crises. This concern is exacerbated by the rising prevalence of multi-resistant bacteria and projections indicating that the next pandemic might be triggered by "superbugs" [19]. These challenges can be overcome by developing efficient and sustainable superhydrophobic materials. As far as we are aware, and likely due to the distinct nature of these research domains, there has not been a unified approach based on cellulose-based superhydrophobic materials that could simultaneously address the two requirements here considered. Cellulose and cellulose materials/fabrics are highly abundant, easily functionalized and of low cost [7]. On the other hand, ILs offer customization, and even within a specific class like quaternary ammonium ILs, there exists a multitude of cation-anion combinations that can be tailored to ensure the suitable characteristics towards a given application. Accordingly, the main objectives of CLEAN are (1) to produce customized superhydrophobic cellulose-based SILs (CSILS) through the covalent bonding of ILs to their surface, thus avoiding the leaching of the IL; (2) assess the antimicrobial properties of CSILs in order to design antimicrobial textiles; and (3) evaluate the adsorption capacity of CSILs for various oils envisaging water decontamination. To achieve the described objectives, cellulose-based materials (cellulose paste, filter paper, cotton pads, and cotton fabrics) functionalized with ILs will be produced employing a method previously optimized by the CLEAN team, although not resorting to superhydrophobic materials and addressing other purposes [18–26]. Initiating the functionalization process with a silanization reaction imparts hydrophobicity to the cellulose surface. Furthermore, by introducing an additional step that involves incorporating quaternary ammoniums, our objective is to augment the bactericidal effect of the resulting cellulose material. The evaluation of the final material's antibacterial and oil/water separation properties will consider factors such as the alkyl chain of the quaternary ammonium, the type of anion, and the degree of functionalization. Focusing on the two fields of application proposed, the validation of the antibacterial behaviour will be conducted against standard and clinically relevant antibiotic-resistant bacteria commonly associated with healthcare-acquired infections, and the material's capacity for oil/water separation will be addressed with various organic compounds of environmental concern (chloroform, n-hexane, toluene, diesel, motor oil).